Elevator.



No. 885205. A PATENTED SEPT. 3, 1907.,

@ATTORNEY ernennen PRATT or NEW YORK, n. v f

No. 865,205. i

Specification of Letters Patent.

Application led January 4,1907. Serial No. 350,745.

Patented sept. '3, 1907.

To all whom it may concern:

Be it known that l, Cnannns R. Panna citizen of the United States` residing atNew York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Elevators, of

which the following is a specification.

The invention relates to hoistingv gear for elevators.

The object gf the invention is to secure stoppages Within positive limits, absolute limit and uniform accoloration of speed, the shortest possible car travel in starting and stopping, smooth motion, dead lookin stopped position, minimum occupancy of space, reduced cost of both installation and operation, and the abolitionof brakes or other additional holding or safety devices.

The invention consists i'n the construction hereinafter set forth, whereby the rotation of the hoisting shaft driven by its motor, is controlled positively by gearing actuated bymeans independent of said motor; also in the combination with such hoisting shaft and motor of an independently actuated Worm and gear, and also in the various combinations more particularly set forth in the claims.

The invention is herein shown applied to an electric traction elevator' mechanism, but is, of course, not limited to employment'in connection with that particular apparatus.

In the accompanying drawings-l`igure l is a front elevation and Fig. 2 a side elevation of my improved in )isting gear for elevators.

Similar numbers of reference indicate like parts.

The main shaft l is supported in suitable bearings 2, and directly driven by the armature ot' electric motor 3. Fast on said shaft are' the grooved pulleys 4. The hoisting cable 5 is attached at one end to the elevator car 6,

passes over the pulleys 4 and s. fixed idler pulley 7 and hasits other end secured to the counterweight 8. Also fixed upon shaft l is e.. gear 9 which engages with the, worm l0, on shaft l1. Said shaft is directly driven by the armature of a second electric motor lf2;

he principal motor 3 is run at slow speed and is to he of sui'licient power to talco the gravity load, The speed of the smaller motor is to be such as to rotate the Worm l0 at such arate as to permit the gear wheel 9 and hence the shaft l to be turno. by the principal motor. The construction of the gear wheel and worm is to be such that the worm cannot be driven by the geur wheel. The power of the smaller inolor need only be a sninll fraction of that of the principal motor, say

' one-tenth.

In operation: circuit being csnibiishcd, and the elevator car being down2 ,bolli pintores Sturt together. M0- tor Il relieves motor nl' ullgijavity loalhand motor .l2 being a. high speed motor lvunder very little load has a uniform speed acceleration.- Hence any jerking by motor 3 at starting is resisted bythe Worm 10, and the car begins its ascent free from the irregular movementsA ordinarily produced when motors of very slow speed are employed for direct driving of the hoisting shaft.

It will be obvious that the rotating worm serves asa means of keeping the vcar at fixedispeed, since said car can neither be raised nor-lowerediany more rapidly or I slowly than the movement of the Worm will allow. I n other words, the motor l2 tends to transmit a motion tothe hoisting apparatus Whichsynchronizes with all normal action of the elevator and positively resists all abnormal action. By normal action of the elevator, I- mean a uniform acceleration 'from a state-of rest toa given speed, maintaining said speed, uniform retardation back to rest again, and holding at rest. Abnormal 'action would be starting too suddenly or by a series olf`- jerks, allowing the car to attain a speed in excess-of predetermined speed, stopping too suddenly, or failing to 'hold the ca'r at rest. f

AThere 'may be disposed in the circuit of the innsilll motor any suitable device, such as a rheostat 13 preferably arranged in the car, for varying the speed of s aid motor. In this Way the vyorm may be rotated at such a rate as to retard thedownward travel of the car when the same is being lowered by the main motor, thus saving current expenditure in the latter.

Accidents involving abrupt descent of the cai' are prevented by the locking action of the worm l0 with the gear 9', and in like manner, upon stoppage, the car is positively held in position.

1. Invan elevator, the combination of a car, two motors, mechanism connecting one orsald motors to said car to operate lthe same'and capable of being driven by the action of gravity on the elevator, and other power transmission means posifively connecting' the other motor to the rstmentioned motor and controlling its movement ln both directions andjwhlch cannot be drlven` by action of gravity on the elevator'but can be vdriven by its motor ln the dlrection such dctlonot gravity would tend to drive lt.

2. ln an elevator, the eombinatlon of a cnr, two motors, mechanism connecting one of saidv motors to said car to operate the same and capable of being driven by the action of gravity on the elevator, and a worm and worm wheel connecting the other motor to said mechanism and which cannot be driven by action of gravity. on the elevator'.

3. lne combination with a rotatable member, of two motors, and two means of power transmlsslon, one of which connects one motor to said rotatable member and can be driven therefrom, while the other power transmission means connects the other motor to the rotatable member and cannot be driven therefrom although its motor can drive lt in either dlrection.

4. In an elevator mechanism of the type hereln set forth, a car, a counter-balance, a cable supporting both car and counterbnlance, a pulley receiving said cable, a motive de vlce, means connecting said motive device to the said pulley and adapted to transmit movement ln both directions between said parts, a worm wheel connected with said pulley, a Worin engaging said worm-wheel, and a separate motive devlqe for driving,r said worm.

In an elevator mechanism of the type herein set forth. a car, a counter-balanc :valable supporting both car and counter-balance, a pulley receiving .said cable, a shaft carryingr said pulley, an electric motor directly coupled to said Shaft, a toothed gear on said shaft, a worin engaging said toothed gear, and a second electric motor for rotating,r said worm.

(i. ln an elevator, tbe combination with a car, a cable connected to said car, and a rotatable member to receive said cable, of drivin,y and controlling mechanisms connected to said rotatable member', each adapted to turn it in either direction and one of them capable of being driven by the action of gravity on the elevator while the other cannot be so driven, and means for supplying' energy.

7. ln an elevator, the combination with a car, a cable connected to said car, and a rotatable member to receive said cable, driving mechanism connected to said rotatable member adapted to turn it in either direction and capable of beim.Y driven by the action of gravity on the elevator, mechanism positively and continuously controlling.: the ro tation ot' said rotatable member, energy to said mechanisms independently.

8. in an elevator, the combination with a car, a cable connected to said car, and a rotatable member-'to receive said cable. a low speed driving motor, power transmission moans connecting s d driving motor to said rotatable lnember to turn it in either direction and capable of beine driven by tbe action of gravity on the elevator, means for positively locking'said rotatable member, and a high speed motor controllingT said locking means.

il. ln an elevator', the combination with a car, a cable connected to said car, and a rotatable member to receive said cable, motive means. means connecting said motive means to said rotatable member to turn it in either di rection and capable of being.;l driven by the action of grav and means for supplying ity on the elevator, continuously operating means for positively locking said rotatable member in any position, and means for controlling theI said locking` means independently of said motive means.

il). 'ibe combination oi' an elevator car, a source of mo' tive power, power transmis ion apparatus connecting said source of power to said car to,operate the same and caA pable ot' beim.: driven by the action of gravity on the-elevator. and controlling means positively connected to said power transmittingl apparatus adapted to synchronize with all normal action thereof and to resist all abnormal action, as set forth.

ll. 'lhe combination of an elevator ear, a source 0f motive power, power transmission apparatus connectingr said source of power to said car to operate the same and capable oi b eing driven by the action of gravity on the elevator, controlling means positively connected to said power transmitting apparatus adapted to synchronize with all normal action thereof and to resist all abnormal action,.as set forth, and means tor regnlatin,V said controlling means.

12. In an elevatom the combination of a car, means adapted to transmit lnotivepovver to said car capable of being driven by the action of gravity on the elevator, and independently driven controlling means positively geared to said transmission means having.: driving and driven members in which the drivin;r member cannot be moved or driven by the driven member.

li. ln an elevator mechanism and in combination with the rotary hoisting' shaft tlicrcot', an electric motor having its armature on said snat't, mechanism for positively controlling the rotation of said shaft, and a second electric motor actuating said controlling, means.'

1n testimony whereof l bave atlixed my signature in presence of two witnesses.

A CHARLES. lt. PRATT.

Witnesses 

